I've got this error when try to connect to your broker: javax.net.ssl.SSLHandshakeException: java.security.cert.CertificateException: No subject alternative names present
I don't know the reason of this mistake, we didn't meat this before. I can only recommend this article: www.littlebigextra.com/how-to-add-subjec...-signed-certificate/
We created self-signed certificate only in one example:https://teslascada.com/HTML/yandex-cloud.html
You can try to create the self-signed certificate like in the example and place it in the broker you use.